Arrangement of an Electrical Machine

ABSTRACT

A drive train for a vehicle provided with an internal combustion engine including a first housing mounted on said engine, a second housing mounted in said first housing, a transmission mounted on the second housing operatively connected to the engine, a transversely disposed shaft disposed in the first housing drivingly connected to the transmission, an electrical motor disposed in one of the housings and operating interconnecting the engine and transmission and a clutch operatively interconnecting a rotor of the electric motor and the transmission.

The invention relates to an arrangement of an electrical machine betweenthe power delivery shaft of an internal combustion engine and aspeed-change transmission for motor vehicles according to the preambleof claim 1.

An arrangement such as this is described by DE 101 52 476 A1 in whichthe electrical machine is designed as a starter-generator device; butthe electrical machine can also drive the motor vehicle in addition orindependently in a hybrid propulsion device. Since the electricalmachine is connected downstream from the internal combustion engine inan arrangement in a motor vehicle, in conjunction with a likewisenecessary starting element, construction problems can arise, especiallyfor a front-side drive unit of a motor vehicle with front-wheel drive ora front axle differential.

The object of the invention is to propose an arrangement of the generictype which is made structurally especially compact and which enables afavorable distribution of the axle weight of the motor vehicleespecially for front-wheel drive or all-wheel drive.

This object is achieved according to the invention with thecharacterizing features of claim 1. Advantageous developments of theinvention are described by the other claims.

It is proposed according to the invention that there is an intermediateshaft between the power delivery shaft of the internal combustion engineand the rotor of the electrical machine and that within the axialdistance which has been formed in this way, the output shaft of thedifferential is positioned for driving a wheel of the motor vehicle,which output shaft runs transversely to the drive axis of rotation. Thisarrangement makes it possible, for example in front-wheel drive of themotor vehicle, to shift the internal combustion engine, with a locationwhich is also determined by the positioning of the front axledifferential, farther to the rear, with a corresponding favorabledistribution of the axle weight. Furthermore, mechanical and structuralconstraints can be corrected by the structural compactness which isotherwise present in the arrangement of the electrical machine and theadjacent starting element, for example, a disconnect-type clutch and/ora torque converter.

In a structurally especially compact arrangement the starting elementwith the rotor of the electrical machine can be assembled into a unitand integrated into the housing of the transmission. It goes withoutsaying that the housing must be adapted and if necessary widenedaccordingly.

Furthermore the intermediate shaft and the output shaft of thedifferential can be located in an intermediate housing on which thedifferential gear is laterally mounted. This results in simplifiedproduction of the components to form premounted units which can then beassembled with the internal combustion engine to form a drive unit.

For this purpose, in a further simplification of installation, the rotorof the electrical machine can be pivot-mounted in the transverse wall ofthe transmission and can be connected via a plug connection to theintermediate shaft in such a way as to transfer torque.

Furthermore, the intermediate shaft can be securely connected to thepower delivery shaft of the internal combustion engine or can be madeintegrally with it and thus can likewise form a preassembly unit withthe internal combustion engine.

In an alternative configuration of the invention, a torsional vibrationdamper can be connected between the power delivery shaft of the internalcombustion engine and the intermediate shaft. The torsional vibrationdamper can, in particular, be a dual mass flywheel (ZMS), with a primarymass attached to the power delivery shaft, which is coupled to theintermediate shaft via damping means and a disk-shaped driver part.Alternatively the ZMS can also be connected between the intermediateshaft and the rotor of the electrical machine. This results in that therotor of the electrical machine and the downstream starting element areadvantageously used as the secondary mass of the ZMS.

Furthermore, the disconnect-type clutch which is used as a startingelement, for example a single-disk, dry friction clutch of known design,can be assembled with the rotor of the device to form a unit in astructurally especially advantageous manner, the disconnect-type clutchbeing able to lie at least partially radially within the rotor.

The ring-shaped rotor here can preferably be located around a cup-shapeddrive part which moreover forms the pressure plate of thedisconnect-type clutch.

The intermediate shaft can be connected securely to the cup-shaped drivepart to facilitate installation and, to be driven, can correspond withthe primary mass of the ZMS via a plug connection.

Furthermore, the intermediate shaft can be pivot-mounted especiallyadvantageously in an intermediate wall section which is attached to thehousing of the transmission and thus can ensure durable andvibration-resistant support of the rotor with the integrateddisconnect-type clutch.

The intermediate wall section can be interrupted at least in the regionof the transversely running output shaft, that is, can potentially bemade only above the output shaft and can carry a bearing, especially anantifriction bearing, for the intermediate shaft.

Finally, the input shaft of the transmission can be pivot-mounted in thecup-shaped drive part and/or in the intermediate shaft.

Two embodiments of the invention will be explained below with furtherdetails. The drawings are roughly schematic.

FIG. 1 shows in a side view an arrangement of an electrical machine witha disconnect-type clutch and a split dual mass flywheel (ZMS) betweenthe power delivery shaft of the internal combustion engine and aspeed-change transmission for motor vehicles;

FIG. 2 shows an alternative arrangement as shown in FIG. 1, but withouta dual mass flywheel as the torsional vibration damping means on thepower delivery shaft of the internal combustion engine; and

FIG. 3 shows a roughly schematic top view of the arrangement as shown inFIG. 2.

The drive arrangement shown as a block diagram in FIG. 1 has an internalcombustion engine 10, a downstream, only partially outlined speed-changetransmission 12, and as the electrical machine a starter-generatordevice 14 with a ring-shaped stator 16 and a ring-shaped rotor 18. Theindicated components are of conventional design for motor vehicles tothe extent not described; thus the transmission 12 can be a manualtransmission or an automatic transmission, the device 14 can be any typeof electrical machine, for example an electrical asynchronousthree-phase machine by means of which the internal combustion engine 10is started and the vehicle can be driven in hybrid drive.

A differential is laterally mounted on to the transmission 12 in amanner which is not visible in FIG. 1; the output shaft 20 of thedifferential underneath the axis of rotation 22 of the drive arrangement10, 12, 14 and running transversely or crossing the axis of rotation 22is routed through the housing 24 (clutch housing) which is locatedbetween the internal combustion engine 10 and the transmission 12 anddrives one wheel of the vehicle (for front-wheel or all-wheel drive) viaa continuing universal joint propeller shaft.

A torsional vibration damper or a dual mass flywheel (ZMS) is flanged tothe power delivery shaft or crankshaft 26 of the internal combustionengine 10 and is composed of a disk-shaped primary mass 28, a dampingmeans 30 which is formed by a spring assembly, and a secondary massstill to be described. The primary mass 28 and the damping means 30 canbe made in the design which is known for ZMS.

A disk-shaped driver 32 engages the damping means 30 in the conventionalmanner and, viewed in the direction of rotation, is coupled to theprimary mass 28 by way of the damping means 30 and is drive-connected tothe intermediate shaft 36 by way of a plug connection 34 with thecorresponding plug teeth.

The intermediate shaft 36 is furthermore pivot-mounted by way of arotationally symmetrical journal 38 which has been molded on in acorresponding bearing hole (without reference numeral) in thedisk-shaped primary mass 28.

The intermediate shaft 36 which is moreover pivot-mounted by way of anantifriction bearing 40 in the intermediate wall 24 a of the housing 24,said wall being made only in sections and above the output shaft 20, issecurely connected to a cup-shaped, rotationally symmetrical drive part42 with the rotor 18 of the device 14 mounted on its outer periphery.

Within the cup-shaped drive part 42 there is a single-disk, dry frictionclutch or disconnect-type clutch 44 of conventional design which is onlyoutlined and which is provided, as the starting element, with a clutchcover 46 which is screwed to the drive part 42 and with a driver plate48 which is positioned in between and which is in turn drive-connectednonrotatably by way of a plug connection to the input shaft 50 of thetransmission 12.

In addition, the input shaft 50 is pivot-mounted in the drive part 42 byway of a bearing site 52. The driver plate 48 of the clutch 44 ispressed by means of a pressing device which is not shown directlyagainst the drive part 42 which is used as the base plate of the clutch44. The actuating means of the clutch 44 is not shown and can be ofconventional design.

The stator 16 of the starter-generator device 14 is integral to thehousing 24 and is connected to the electrical system of the motorvehicle and to the corresponding electronic control. When thetransmission 12 has been shifted into neutral and/or when thedisconnect-type clutch 44 has been opened, the internal combustionengine 10 here can be started by current being supplied to the device14, and later, with the internal combustion engine 10 running, it can beconnected as a generator for power generation. Furthermore, optionallyby way of the device 14 in a hybrid drive design the vehicle in additionto the internal combustion engine 10 can be electrically driven.

Based on the described arrangement, the driver 32, the intermediateshaft 36, the drive part 42 with the rotor 18 and with the integratedclutch 44 form the secondary mass of the ZMS which is coupled to theprimary mass 28 damped against torsional vibrations by way of thedamping means 30.

The length of the intermediate shaft 35, as is apparent, is computedsuch that there is the required free space for the transversely runningoutput shaft 20.

FIGS. 2 and 3 show another version of the invention which is describedonly to the extent in which it differs significantly from FIG. 1.Functionally identical parts are provided with the same referencenumerals.

The intermediate shaft 36′ here is directly connected to the powerdelivery shaft 26 of the internal combustion engine 10 (for example by aflange connection) or is molded directed to it, and extends through aseparate intermediate housing 54 which is located between the internalcombustion engine 10 and the transmission 12.

The output shaft 20 of the front axle differential 56 (cf. FIG. 3)extends underneath the intermediate shaft 36′ running transverselythereto; the differential is mounted laterally on the intermediatehousing 54 and as is apparent, in its longitudinal extension can projectover the housing of the internal combustion engine 10 and of thetransmission 12. The internal combustion engine 10 and the transmission12 can thus be placed relatively close proximity to one another.

The electrical machine 14 with its stator 16 and the rotor 18 is locatedwithin the housing 12 a of the transmission 12 behind an input-sidetransverse wall 58, the rotor 18 in the transverse wall 58 beingpivot-mounted by way of an antifriction bearing 60 and in a manner whichis not detailed bears the disconnect-type clutch 44 as the startingelement in a unit. The clutch actuation 52 which is only outlined islikewise integrated in the transmission 12.

The transverse wall 58 is made as a separate intermediate wall for asimplification of the installation of the transmission 12 with theelectrical machine 14 and the disconnect-type clutch 44 and ispositioned and attached in the flange region between the intermediatehousing 54 and the housing 12 a of the transmission 12.

The intermediate shaft 36′ is nonrotatably connected to the rotor 18 ofthe electrical machine 14 by way of a plug connection which is uniformlydesignated as 64.

The invention is not limited to the illustrated embodiments. Thus,instead of the described disconnect-type clutch 44, a double clutch, ahydraulically actuated multiple-disk clutch, etc., can also be used,depending on the type of transmission. The housing 24 can be the clutchhousing which is conventional for transmissions 12 and which is flangedaccordingly to the housing of the internal combustion engine.

In the version according to FIGS. 2 and 3 there can likewise be atorsional vibration damping means or a ZMS which can be mountedaccordingly in the conventional manner on the disconnect-type clutch 44.Alternatively the torsional vibration damping means or the ZMS can belocated within the intermediate housing 54 and between the output shaft20 of the differential 56 and the transmission-side transverse wall 58,as indicated by the broken lines in FIG. 2. The intermediate shaft 36′could be made in two parts for this purpose, with one shaft segmentconnected to the power delivery shaft 26 of the internal combustionengine 10, and one shaft segment connected to the rotor 18 via the plugconnection 64; the two shaft segments would have to be pivot-mounted inone another similarly to FIG. 1.

1. An arrangement of an electrical machine between the power deliveryshaft of an internal combustion engine and a speed-change transmissionfor motor vehicles, the electrical machine consisting of a rotor orstator being combined with a starting element which interrupts the flowof power wherein there is an intermediate shaft between the powerdelivery shaft of the internal combustion engine and the rotor of theelectrical machine and that within the axial distance which has beenformed in this way the output shaft of the differential is positionedfor driving a wheel of the motor vehicle, which output shaft runstransversely to the drive axis of rotation.
 2. The arrangement accordingto claim 1, wherein the starting element with the rotor of theelectrical machine is assembled into a unit.
 3. The arrangementaccording to claim 1 wherein the electrical machine and the startingelement are integrated into the housing of the transmission.
 4. Thearrangement according to claim 1 wherein the intermediate shaft and theoutput shaft of the differential are located in an intermediate housingon which the differential gear is laterally mounted.
 5. The arrangementaccording to claim 1 wherein the rotor of the electrical machine isjournaled in a transverse wall of the transmission and is connected viaa plug connection to the intermediate shaft to transfer torque.
 6. Thearrangement according to claim 5 wherein the intermediate shaft issecurely connected to the power delivery shaft of the internalcombustion engine or is made integrally with it.
 7. The arrangementaccording to claim 1 wherein a torsional vibration damper is connectedto the intermediate shaft between the power delivery shaft of theinternal combustion engine and the rotor of the electrical machine. 8.The arrangement according to claim 7 wherein the torsional vibrationdamper is a dual mass flywheel (ZMS) with a primary mass attached to thepower delivery shaft, which flywheel is coupled to the intermediateshaft via a damping means and a disk-shaped driver part.
 9. Thearrangement according to claim 7 wherein the torsional vibration damperis a dual mass flywheel (ZMS) with a primary mass attached to theintermediate shaft, which flywheel is drive-connected to the rotor via adamping means and a disk-shaped driver part.
 10. The arrangementaccording to claim 1 wherein the ring-shaped rotor (18) of theelectrical machine (14) is located around a cup-shaped drive part (42)which moreover forms the base plate of the disconnect-type clutch (44)which is provided as the starting element.
 11. The arrangement accordingto wherein the intermediate shaft is securely connected to thecup-shaped drive part and to be driven corresponds with the disk-shapeddriver via a plug connection.
 12. The arrangement according to claim 1wherein the intermediate shaft is journalled in an intermediate wallsection which is attached to the housing.
 13. The arrangement accordingto claim 12 wherein the intermediate wall section is interrupted atleast in the region of the transversely running output shaft.
 14. Thearrangement according to claim 1 wherein the input shaft of thetransmission is journaled in one of the cup-shaped drive part and theintermediate shaft.
 15. A drive train for a vehicle provided with aninternal combustion engine, comprising: a first housing mounted on saidengine; a second housing mounted on said first housing; a transmissionmounted in said second housing; a transversely disposed shaft providedwith a differential gear assembly mounted on said first housing; andmeans for transferring torque from said transmission to saiddifferential gear assembly.
 16. A drive train according to claim 15including a electric motor mounted in said second housing having astator and a rotor operatively connected to said engine and to saidtransmission.
 17. A drive train according to claim 16 wherein said rotoris drivingly connected to an output of said engine by means of a shaftextending through said first housing.
 18. A drive train according toclaim 16 including a clutch disposed between said rotor and saidtransmission.
 19. A drive train according to claim 16 wherein saidstator is electrically connected to an electric energy storage means.20. A drive train according to claim 17 including torsional vibrationdampening means disposed between said engine output and said shaftwithin said first housing.